Soldering, brazing, and welding fluxes



Patented Nov. 2, 19418 pairs at OF FlCE L Lionel Cinalnon, NewYork, N. Y.

No Drawing,

. This invention relates to fluxes, and more par ticularly to a noveland highly improved composition for soldering, brazing and welding and non-ferrous metals and the alloys thereof.

..In this art, various compositions have been used fluorides are essential constituents of the flux. These fluxes are used in the form of their alkali, neutralor acid salts of hydrofluoric acid or of the complex si1ic o-, titano-, b-oro.-, fluoricacids, and the like. However, these fluxes have not afforded the universality of use for I Even when they worked satisfactorily for a specific meta1,..they' proved objectionable with other metals because of their discoloring eiv 'fects, pitting, uneven wetting action, and the like. Furthermore, the freezing point of such composttions is higher than that regarded as desirable. It also has been noted with grave concern that these fluxing compositionshave a great tendency to crystallization, and as a consequence their'shelf life is shortened.

Accordingly, the objects of this invention are to provide a composition which: (a) ,isadapted for use as a flux in the soldering, brazing andwel ding of "a great variety of metals and alloys; (19) does not discolor the metals and alloys; has anadvantageously low freezing point; i (d) minimizes pitting and pinholes; (c) has an improved wetting aotionso as to cause the solder to flow and spread for fluxing purposes wherein more readily; (1) maybe easily washed away in the customary fashion after the operator has com.- pleted theunion of the metals and alloys; and (g) has a markedly decreased tendency to crystallize. The essence of the invention which renders the foregoingobjects possible of accomplishment resides in the incorporation in a fluxingcomposition of the fluoride type oiphosphorus compounds.

Among, the phosphoruscompounds discovered which produce excellent resultsin these composi..-,

tions are the acids and various salts of phosphoric:

acid, pyrophosphoricacid, metaphos'phoric acid, hypophosphorus acid, the acids and salts derived from P406, P204, and the like.

It is to be noted thatany salt of an acid of phosphorus may he prepared from the alkali metals. ammonia and'other compounds related thereto. I

The following examples in .Whichtlfie proportions are given by weight are illustrativem the invention: a

Example I Afiux is prepared from: M i i i Grams Water n 92.8 Potassium acid fluoride .400 Borax 15.2 Potassium silicofluoride N 20 0.0 Boric acid a 152.0

1 To 100 grams of the-aioresaidflux there -were d lineation setamamama; f derial No.

laims. (01. 148

of ferrous from 10 to50 grams wh in the pH from approxim addedphosphoric acid in effective increments oi from 10 to 50 grams which produced variations; in the pH from approximately ele-ctrometrically) Among the improvements observed it was noted that the phosphorated flux decreased the pitting action on nickel. 1 L

To grams of the aforesaidfiuxithere were added. xzneoasnzom effective increments of from 5 to grams which produced 'variations in the pH from approxim'atelyfifi to 'Mrilt was observed that the lower increments of the phos 'pholus compound produced a marked improvement in the wetting action, cleaning of themtal and, soldering action on metals such as copper, brass, nickel, iron and stainless steel; and. that this effectiveness remained practically unimpaired at the 150 grams increment level.

To 100 grams of the aforesaid fiux therewere added a mixture composed of KzHPOiiappro'xi mately 1 part) "and 'KHzPOr approximatelyA' parts) in grams so that the pH ofthe hosphorized flux re-r mained relativelyqconstant. .It was noted that his flux produced a markediimprovement in the cleaning-of nickel. q y it it Q The electrornetric pl-I. determinations in the foregoing. cases,yas well asin all thosejhereinafter described, were carried out in accordance with the following procedure: 5 grams of a composition are suspended in 50 cc. of distilled wateratroomtem- Beckmanelectrometric pH meter. l i

To 10o grains ofthe aforesaid flux therewere added phosphoric acid in effective increments of ich produced variations the improvements observed,..itwas noted that the phosphorized flux produced a marked increase in wetting action on stainlesssteel; decreased the discoloring of iron and stainless steel; and de creased the pitting of iron.

To 100 grams of theaforesaid fiuxthere were added K2HPO4.3HZO in efiective increments of from 5 to 200 grams which produced variatlonsin the pH fromapproximately 6.8to 7.4." It was observed that increments of froml5 to 150 grams of thephosphorus compound improved the wetting actionand cleaning of the metal inthe caseof Higher increments imPrOved 5,6 to it? (determined effective increments. of ,from 10; to 50 To 100 grams of the aforesaid..flux,.thererwere; added phosphoric acid in effective irlcremen tsofj from 10 to 50 grams which produced variations in the pH from approximately 6.0 to 2.7. Amongthe improvements observed, it was noted that the wettinggxaction on thefer-rousmetals; improved cleaning ofcopper,. brass,- nickel and iron .v

To 100 added K2HP0413H2G (in efiectivedncrements of from 5 to. 150igrams which: produced :variations in the pH from approximately 628 to 7 3'.- It was observedthat;these-.phosphorized fluxes produced marked improvementsimiwetting actiomon-copper," brass, nickelnand/stainless steel; and decreased-.theepitti-ng .action 'on. thesezmetals as well as iron... 7

Example I Vs A'fiux is prepared from Grams Water. 120' Potassium acidfluoride 234 Boricpacid .93

' nickel and stainlesssteel.v

To 100 .gramsof .the aforesaid l'fluxr-theres ere added a mixture compsednf lK2HPU4 {approxii mately 1 .part'); andnK-HQPBQ. (approximately 9 I parts) in. effective incrementsof. l2.to GO'Lgrams sothat the. pH. .of the .phosphorized. .flumremained relatively. constant. It wasanotedw that these. fluxes. ,producedca. .marked improvement r in. .the cleaning of) nickel andiron.

Example V' A fluxiisnpreparedfrom:

Grams Water 1'00" Potassium: zca'rb'bnateeufl 6:5 Potassium-acid fiuoridee"- 38:5 Potassium.fiuoride; 136 Potassium. borofluoride' ;(KBF4-).: 23:15 Potassiumzsilico fluoride 3.85: Borickacidn. .192

Tdillfl ggnamsoithe v-;at.oresaid.flux. there .were adQEdQEHPOLiH-IQO L in; effective eincrements .-of from to 150 grams which produced variations in! grams of .the aforesaidflux .therewere Boric acid the pH from approximately 6.9 to 7.4. It was ob served that these phosphorated fluxes produced improved wetting-action lonrmetals suchv as copper;'f-brass; nickel, iron. and. stainless steel; improved cleaning of iron and stainless steel; and

decreased pitting of copper.

Example VI A flux is prepared from:

Grams Water 120 Potassium carbonate Potassium acid fluoride; 240 Boriczacim; 80

To grams of the aforesaid flux there were added phosphoric acid in elfective increments of from" 10 to '50 gramswhich produced variations in the'pH from approximately 6.2 to 4.9. Among the improvements observed, it was noted that the phosphorized flux produced a marked improvementin wetting action on nickel and stainless steel; 'animprovement in cleaning action on copperand stainless steel.

To 100 grams of-"the aforesaid flux there'were added K2HPO4BH2O in efiective increments of from 5 to *grams which produced variations in the pHfrom approximately 6.1 to 6.5. It was 'observed thatthehigher increments of the phos-' phorus'compound produced I ment in the Wetting action ofthe fiuxesron copper, brass; nickel and stainless steel.

Example VII To 100 grams of the aforesaid fiux there were added Phosphoric acid in effective increments of from-1'0 to "50 grams-which produced variations in the pHifr'om approximately 6.1 to 3.8. Among the dm'provem'ents' observed, it was noted that the phosphorized fiuxesshowed improved wetting ac tio'n on copper and iron; improved cleaning of nickel and iron; and decreased pitting of copper and iron? marked improvements in wetting'action on copper-andnickeki proved cleaning of nickel; and decreased pitting of copper.

Example VIII Afiux'is preparedfrom:

Grams Water, .120 Potassium carbonate; 68 l I Pdtassimnacid fluoride 200 132 'cleaningaction on brass and nickel.

To 100' grams of the aforesaid flux there wereaddeda EQe3HzQ-imerfective:incrementsmf improvement in'the from 5 to'200. grams which produced variations in the pH from approximately GA to 6.8. It was fluxes show marked improve observed that these ments "in wetting action on nickel; improved To 100 grams of the aforesaid flux there were added K2HPO4.3H2O in effective increments of from 5 to 150 grams which produced variations in the pH from approximately 6.2 to 7.7. It was observed that these fluxes showed a marked improvement in wetting action on metals such as copper, brass, nickel, iron and stainless steel; improved cleaning action on iron; and decreased pitting of stainless steel.

Example X A flux is prepared from:

. Grams Water 90 Borax 25 Sodium acid fluoride Boric acid 375 To 100 grams of the aforesaid flux there were added phosphoric acid in effective increments of from 10 to 50 grams which produced variations in the pH from approximately 2.0 to 1.5. Among the improvements observed, it was noted that the phosphorized flux decreased the pitting action on brass.

To 100 grams of the aforesaid flux there were added KzfHPOaiiI-IzO in effective increments of from 5 to 150 grams which produced variations in the pH from approximately 5.8 to 7.4. It was observed that these fluxes showed a marked improvement in wetting action on copper, brass, nickel, iron and stainless steel, and decreased pitting of brass and iron.

To 100 grams of the aforesaid flux there were added a mixture composed of KZHPOc (approximately 1 part) and KI-121 04 (approximately 5 parts) in effective increments of from 12 to 64 grams so that the pH of the phosphorized flux remained relatively constant. It was noted that this flux produced a marked improvement in the wetting action on copper.

Example XI A flux is prepared from:

Grams Water 100 Potassium tetraborate (K2B40m5H20) 160 Potassium acid fluoride 20 Boric acid 160 in the pH from approximately- 6 :3 to -8.3.' It was observed that"thesephosphcrized :fluxes 'pro-I duced marked improvement in wetting action .on metals such as copper, brass, nickel, iron and stainless steel; a marked improvement in cleaningac'tionbn' copper; and decreased pitting of brass, iron and stainless steel V To 100 gramspf the aforesaid flux there were added amixture composed of ,K2HPO'4 (approximately r-parts)" and KmPo (approximately 1 part) in effective increments of 15 to grams so that the pH of the phosphorized flux remained relatively constant. It was noted that these fluxes showed a marked improvement in the cleaning of brass.

Example XII A flux is prepared from:

Grams Water 96 Potassium hydroxide 156 Potassium acid fluoride 380 Boric acid 690 Potassium silico fluoride 0.375

To 100 grams of the aforesaid flux there were added K2HPO4BH2O in effective increments of from 20 to 100 grams which produced variations in the pH from approximately 6.6 to 6.8. Among the improvements observed, it was noted that these fluxes showed a marked increase in wetting action on copper, nickel and iron; and in-..

creased cleaning action on nickel.

To 100 grams of the aforesaid flux there were added a mixture composed of K2HPO4 (approximately 1.3 parts) and KH2PO4 (approximately 1 part) in effective increments of 14 to '70 grams so that the pH of the phosphorized flux remained relatively constant. It was noted that these fluxes, in the higher increments of the phosphorus containing mixtures, showed an improved cleaning action on nickel.

It is to be understood that the foregoing examples are merely illustrative of the fluxes which may be improved so advantageously by the incorporation therewith of various phosphorus compounds. It is further to be understood that the phosphorus compounds include phosphides, phosphonium compounds and other phosphorus containing materials of organic and/or inorganic structure. All the phosphorus compounds may be used either singly or in various combinations with each other for incorpo- I claim: 1. In a flux embodying boric acid and an alkali fluorine compound the improvement which comprises: the combination with said flux of a member of the group consisting of an acid of pentavalent phosphorus and the alkali metal salts thereof.

2. In a flux embodying boric acid and an alkali fluorine compound the improvement which comprises: the combination with said flux of a member of the group consisting of an acid of pentavalent phosphorus and the alkali metal salts thereof which imparts a phosphorus content to the flux of approximately 0.65% to 9.2%.

3. In a flux embodying boric acid and an alkali fluorine compound the improvement which comprises: the combination with said flux of an. alkali metal salt of an acid of pentavalent phosphorus.

4. In a flux embodying horic acid and an alkali fluorine compound the improvement which com- Epst i Jun 1942 OREIGI? PA S J Number Country- Date The" tdlmwing references: 'areaof'iremrdi; my? th;

i; 1081 778 Great Britain Aug. 23,1911 I file ofiinhismatienw 

